Altered spontaneous brain activity pattern in patients with high myopia using amplitude of low-frequency fluctuation: a resting-state fMRI study

Figures & data

Table 1 Demographics and clinical measurements by group

Variable	HM	HC	t-test	P-value*
Male/female, n	17/21	17/21	N/A	>0.99
Age (years), mean ± SD	22.76±1.28	22.71±1.23	0.183	0.856
Weight (kg), mean ± SD	65.21±6.89	65.26±6.31	−0.035	0.972
Handedness, n	38R	38R	N/A	>0.99
Duration of HM (years), mean ± SD	6.34±1.12	N/A	N/A	N/A
Refractive diopter-right (D), mean ± SD	−641.05±37.04	N/A	N/A	N/A
Refractive diopter-left (D), mean ± SD	−643.68±37.59	N/A	N/A	N/A
Best-corrected VA-right eye, mean ± SD	1.15±0.16	1.13±0.15	0.381	0.705
Best-corrected VA-left eye, mean ± SD	1.14±0.14	1.14±0.16	−0.076	0.940

Note:

* P<0.05, independent t-tests for comparing two groups.

Abbreviations: HC, healthy control; HM, high myopia; N/A, not applicable; R, right; VA, visual acuity.

Figure 1 One-sample t-test results. Within-group ALFF maps within the HM (left) and HC (right) groups (P<0.001, FDR corrected).

Abbreviations: ALFF, amplitude of low-frequency fluctuation; FDR, false discovery rate; HC, healthy control; HM, high myopia; LH, left hemisphere; RH, right hemisphere.

Figure 2 Spontaneous brain activity in the monocular blindness and healthy control groups.

Notes: Significant differences in activity were observed in the right inferior and middle temporal gyrus, left middle temporal gyrus, left inferior frontal gyrus/putamen, right inferior frontal gyrus/putamen/insula, right middle frontal gyrus, right inferior parietal lobule, bilateral midcingulate cortex, left postcentral gyrus, and left precuneus/inferior parietal lobule. The red or yellow areas denote higher ALFF values and the blue areas indicate lower ALFF values (P<0.01 for multiple comparisons using GRF theory) (z>2.3, P<0.01, cluster >40 voxels, AlphaSim corrected).
Abbreviations: ALFF, amplitude of low-frequency fluctuation; GRF, Gaussian random field; L, left; LH, left hemisphere; R, right; RH, right hemisphere.

Figure 3 The mean values of altered ALFF values between the HM and HC groups.

Abbreviations: ALFF, amplitude of low-frequency fluctuation; HC, healthy control; HM, high myopia; IFG, inferior frontal gyrus; IPL, inferior parietal lobule; IS, insula; ITG, inferior temporal gyrus; MCC, midcingulate cortex; MFG, middle frontal gyrus; MTG, middle temporal gyrus; posCG, postcentral gyrus; preCU, precuneus; PT, putamen.

Table 2 Brain areas with significantly different ALFF values between the groups

Brain areas	MNI coordinates			Voxels	BA	L/R	Peak t-values
	x	y	z
HM < HC
Inferior and middle temporal gyrus	60	−27	−18	147	20.21	R	−5.323
Middle temporal gyrus	−63	−33	−15	68	21	L	−5.681
Inferior frontal gyrus/putamen	−21	24	−21	119	47	L	−5.975
Inferior frontal gyrus/putamen/insula	21	15	−6	450	47.13	R	−7.484
Middle frontal gyrus	33	24	39	86	9	R	−6.986
Inferior parietal lobule	51	−33	30	60	40	R	−6.631
HM > HC
Midcingulate cortex	9	−3	39	59	24	B	5.874
Postcentral gyrus	−39	−15	54	159	3	L	6.679
Precuneus/inferior parietal lobule	−27	−48	48	37	40.7	L	6.479

Note: The statistical threshold was set at the voxel level with P<0.05 for multiple comparisons using GRF theory (z>2.3, P<0.01, cluster >40 voxels, AlphaSim corrected).

Abbreviations: ALFF, amplitude of low-frequency fluctuation; B, bilateral; BA, Brodmann area; GRF, Gaussian random field; HC, healthy control; HM, high myopia; L, left; MNI, Montreal Neurological Institute; R, right.

Figure 4 ROC curve analysis of the mean ALFF values for altered brain regions.

Notes: The AUCs were: 0.744 (P<0.001; 95% CI: 0.634–0.855) for the right ITG/MTG, 0.734 (P<0.001; 95% CI: 0.634–0.845) for the left MTG, 0.713 (P=0.001; 95% CI: 0.598–0.828) for the left IFG/PT, 0.725 (P=0.001; 95% CI: 0.611–0.839) for the right IFG/PT/IS, 0.783 (P<0.001; 95% CI: 0.677–0.888) for the right MFG, and 0.729 (P=0.001; 95% CI: 0.616–0.841) for the right IPL (HMs < HCs) (A). The AUCs were: 0.643 (P=0.032; 95% CI: 0.519–0.768) for the bilateral MCC, 0.679 (P=0.007; 95% CI: 0.558–0.801) for the left posCG, 0.659 (P=0.017; 95% CI: 0.536–0.783) for the left preCU/IPL (HMs > HCs) (B).
Abbreviations: ALFF, amplitude of low-frequency fluctuation; AUC, area under the curve; CI, confidence interval; HCs, healthy controls; HM, high myopia; IFG, inferior frontal gyrus; IPL, inferior parietal lobule; IS, insula; ITG, inferior temporal gyrus; MCC, midcingulate cortex; MFG, middle frontal gyrus; MTG, middle temporal gyrus; posCG, postcentral gyrus; preCU, precuneus; PT, putamen; ROC, receiver operating characteristic.